The integration of spatial information into relational database management systems continues to develop both in scope and scale to provide users (for example, application developers, data providers and data users) the ability to explore new opportunities requiring the analysis of multi-dimensional data. In the past, the spatial world thought it only needed to be two dimensional (2D) to support the needs for effective data representation and display. In certain cases, an ability to assign a Z-coordinate value to a specific coordinate or series of coordinates would be described as 3D data. However, while the typical approach of integrating a 2D model with a 3D surface representation, which is commonly known as a two and a half dimensional (2.5D) representation, works for many categories of queries, it is not accurate for true 3D data that can support volumetric analysis.
The volumetric character of data often becomes important when considering detailed, through-space interactions between features, such as the interactions that occur in urban environments or complex navigational planning. Volumetric models are the most complex and most expressive tools available for describing interactions in the real world.
As a result, the need for and ability to analyze and manipulate true 3D data is rapidly increasing. Unfortunately, existing geographic information systems (GIS) functionality only provides for data analysis, structuring, management and presentation of 2D and 2.5 D data. Similar capabilities operating within a true 3D topology model will allow application developers to better serve users of spatial information and expand the areas and complexities associated with modeling and analyzing real world data. For example, 3D urban planning, defense, medical analysis, monitoring of complex environmental factors, telecommunications, management of utility assets, mining and underground detection are just a sample of pursuits that stand to benefit from the availability of a true 3D model.